Multilayer cards are known comprising a core layer, forming the body of the card, a printed layer on which the data appears and that extends over the core layer, and a transparent protective layer extending on the printed layer. The core layer and the protective layer are generally made of polyethylene terephthalate which is a material that withstands external aggression and that is relatively inexpensive. The printed layer is made of polyvinylchlroide which is a material that is particularly well adapted to printing.
Such a card is made by lamination. Unfortunately, with that method, the adhesion of the protective layer of polyethylene terephthalate on the printed layer of polyvinylchlroide is relatively weak so there exists a risk of an unauthorized person unsticking the protective layer from the printed layer in order to falsify the data that appears thereon.
To obviate that drawback, it is known to make a protective layer that is fragmented. The protective layer then cannot be withdrawn as a single piece, which makes it more difficult to remove and to put back into place. Unfortunately, such fragmentation also complicates manufacture of the card.